When zoo staffers gave Patrick toys to play with, he would tear them up and eat them. He was known to throw rocks at the observation glass.

“I’m told he has a thing for women with toenail polish. If visitors stand outside the exhibit with painted toenails, he’ll tap the glass and point,” Kramer said. “I’ve never seen that myself.”

In any case, Tufani and Makena were shipped to the Kansas City Zoo in Missouri. In the years that followed, Patrick spent much of his time alone or, more recently, as part of a bachelor gorilla troop that zoo officials are putting together.

Now, zoo officials are trying once again to improve Patrick’s social skills.

Earlier this year, Kramer received approval from the Species Survival Commission, which oversees the placement of endangered animals, to temporarily acquire two new female gorillas.

Madge, 30, and Shanta, 15, arrived in Dallas from the Cincinnati Zoo last month and are in temporary quarantine.

Maria Ross, a Dallas Zoo mammal keeper, spent time at the Cincinnati Zoo observing their behavior before bringing them down to meet Patrick.

Unlike Dallas, the Cincinnati Zoo has a large troop, where the two females were well-schooled in proper primate behavior. Ross said.

“They’re used to silverbacks; they’ll know how to act,” she said. “They’ll be nonconfrontational, but they’ll stand their ground.”

Kramer said he believes that like a lot of troublesome young males, Patrick is a product of a poor upbringing.

Born in the Bronx Zoo, he was hand-raised by humans, Kramer said. Once in Dallas, he was partnered with Jabari, another young male gorilla. After Jabari was killed by Dallas police during an escape in 2004 that injured three zoo visitors, Patrick spent years largely by himself.

None of this worked to foster good gorilla manners.

If anything, Kramer said, he is surprised that Patrick’s behavior is as normal as it is.

Unlike some silverbacks raised by humans, Patrick doesn’t walk upright on two legs but drags his knuckles as a gorilla with any pride should. He doesn’t stare at other gorillas (which indicates hostility) but glances sideways.

Patrick’s basic problem, Kramer said, appears to be boredom.

“He’s a bit hyper,” he said, “but I also think he’s beginning to mellow out a little bit.”

We’ll know soon enough.

The first step is putting the prospective love interests in adjacent enclosures — a process known as the “howdy phase.” Then, if all goes well, they will be introduced soon.

If everything goes really well, Patrick and Shanta may get approval from the Species Survival Commission to mate.

Patrick would then be allowed to join a full-fledged breeding troop. If that doesn’t work out, then he may be consigned to the Dallas Zoo’s bachelor troop.

And if he can’t even get along with the other guys, then it may be back to life on his own. Kramer considers that to be the least likely outcome.

Still, he said: “Patrick has one strike against him. If he can’t be socialized with them (Madge and Shanta), then I don’t think the SSC will be inclined to send us any more. At this point it all depends on his own behavior.”